- Heat the oil in a large saucepan.

- Add the onion and on medium, stirring occationaly until soft & lightly browned.

- Stir in the sun-dried tomato paste, chopped tomatoes, zucchini, diced potatoes, and garlic and cook slowly for 10 minutes, uncovered, shaking the pan frequently to stop the vegetables from sticking to the base.

- Pour in the stock or water and bring to a boil.

- Lower the heat, partialy cover the pan, and simmer for 15 minutes, or until the vegetables are just tender.

- Add more stock if necessary.

- Remove the pan from the heat and stir in the basil and half the cheese. Taste and adjust the seasoning. Serve hot, sprinkled with the remaining cheese.